Pulse-echo acoustic ranging systems, also known as time-of-flight ranging systems, are commonly used in level measurement applications. Pulse-echo acoustic ranging systems determine the distance to a reflector (i.e. reflective surface) by measuring how long after transmission of a burst of energy pulses the echo or reflected pulses are received. Such systems typically use ultrasonic pulses or pulse radar signals.
Pulse-echo acoustic ranging systems generally include a transducer and a signal processor. The transducer serves the dual role of transmitting and receiving the energy pulses. The signal processor is for detecting and calculating the distance or range of the object based on the transmit times of the transmitted and reflected energy pulses.
Since the transmitted energy pulses are converted into distance measurements, any timing errors arising in the circuitry of the device result in distance measurement errors which degrade the accuracy of the level measurements. In most cases, timing errors are a result of temperature drift and drift over time in the operating characteristics of the electronics in the device circuitry. Accordingly, it is necessary to re-tune time-of-flight ranging systems not only at installation, but on a periodic basis as well in order to ensure accurate level measurements.
While there is a need to periodically tune filters, the time-of-flight ranging systems are not always easily accessible after installation. In addition, there is a cost involved with a technician conducting calibration tests on an ongoing basis.
Accordingly, there remains a need to provide a system and techniques which facilitate dynamic tuning of a filter in pulse-echo or time-of-flight ranging systems while overcoming these and other perceived shortcomings.